Method of molding structural slabs of cement and fiber



Sept. 25, 1951 METHOD OF MOLDING STRUCTURAL SLABS OF CEMENT AND FIBER s. w. EvENsEN 2,569,157

Filed July 8, 1949 fnz/enoff jverre ZULLZ/[redEr/ene 72,

Patented Sept. 25, 1951 METHOD OFMOLDING STRUCTURAL SLABS'OF GEMENT Sverre WilfrediE-Yensen, FredrilsstadnNorwar -4 .Claims I'he `presc-:nt.invention@relates to aimethodfof .manufacturing constructional .plates :and 'the like :which consist.. of woodsshawings, excelsiorzor .similar .strips of bres..of,.a .substantial olengtih,

, the .cross section. of :suchstripsphaving a greater `width thanthickness.

.;Such.- stripszfby:means Aof cement and water` orsother..suitablebondngimaterial are formed into plates suitable-:iter .con-

structional. purposes.

Ityhas been .previously proposedfan d alsopracfticed, to Vmanufacture :Suchplates by mixing the Vfibermaterialin `question,say excelsior or straw,

.with a suitable v.bonding .,agent, lfor Vexample .ce-

. ment .and water, fand if desired, ladditional constituents l.making `the yginalproduct resistive to .,re, water, frost, .fungi :and other decay, Whereafter such mixtureis` formed into disc-likes bodies whichare subjected tofpressure at .right angles tothe largeriace surfaces of said bodies, andare ymaintained under. pressure until the bondingsub-I stance has set suil'icientl-y, .so `that the plate .Y formed Vwill mamtain the yshaps :and i.divxnensions obtained by s uch operation.

In this manner @constructional plates.y have )been ,obtained vwhich :were utilizable as .'.insula-tion boardsfandfwhich have ,other severalnurposes- The applicant has found, that by-fa flllysiml-fple .manner of working it isposs-ible;tormanufac- ;ture ,constructional plates .whichhavaguite lastonishing vproperties as :compared with plates manufacturedbythe. methodslihitherto known.

The primary feature of the invention consists in that Vthe liquid lmixture confined in a mold is .subjected .to pressure which is directed substantially parallel to the large or face surfaces of the finished plate. In this manner the o1'- ganic liber `material will-tumble or'tilt over and in the finished product wil-l act somewhat as l planks :standing .onledge Thus the :finished plate will yhai/ea. .denser structure and, addition. `to having .heat insulatingfproperties, i itwill valso have increased mechanica1 strength so that the plate may be used to form intermediate walls, outer Walls, floors or ceilings or parts thereof, or, in general, sustaining constructional members in small buildings, or may be used as insulating boards in connection with brickor bton walls. 'Ihus it has been found that such plates may be used directly as intermediate walls in buildings, and that sinks or -other similar heavy devices may be secured directly thereto by screws or the like. Of course, such intermediate walls would, if desired, be provided with a cover of w-all paper or a coat of paint.

In the manufacture of insulating plates or .-.a iturrzrblinglor :tilting overtof .thas ,steriel hichare not,aiready:positionedgwitntheir .1ere-e.-surfenmsubstantiallygatir vdirection.of theforesslire. lBut boards of lthefztyperaboszementioned as. in

.thefprlorant-aia from the-:large rfa'ce surfaces ofzi'fhe nlateszthereavillrotcoursenoccur rips, @Linaa .ng'lQS lille such saseths maiorfnortion'tsfgthesstrip a. @come biased with their lares surfaces fnarallsl ato the dares v fase.- surfasss-sffthe. .slatsffl-whsrsastheyf- -whsnfthegmethsdtsf this invention` ussdfwill have their large .surfaces -.situated 2.more ,pr less .at-right anglssfto theflarss fase Tsurfaces.of ,the n.nishedplate. ,-I-t is\be1ievd v.that this Vis Lthe 'reason l :why plates produced eacoordance E'with the) present-.inventioneareaso much-,stronger Ithan l-plates .produced@coordinata-knownlmethods. :a1-

,thoilgh the -nlatesamarwiactured -in accordance ...with thegpresent-g-.inventen stilllm re V,relnarkable insulatillahrsperties.

Eer the Lproduction :of plates-.in ,accordane with thetpresentfinventonjapentainguantity. pr .volume tof therflbermaterialin question-to which .has been added bondinglagent land eventually ,otherfdesired additionahsubstances. ist-nlasedfin a mold, whereafterthisonass .is subjectedtoprsssure-.parallel orsubstantidbaparaHshtottheiarge fase rsuriacesof .the plate. vrSuch pressure .may 4beexerted; iromlonai-twdor foin sides,

and .may .take'place ...by such-means Lha'tfbn one side :fof thednshedlllate, .there will vbe formedL a .groove and on the Lothar :.side a tongue ,Such vtenses/e alidftolleue may be,.adantaeeclus when the ,plates are lo .beambnedsto ,forniintermediate .Walls and thetlike. A

@urine vthe nressinsf-operationtne ,molds .be -Nertically positioned -several molds being ...placed .fad-jacent to-feachrother, yand Jthe-material slclesgeffthe-.olate tolsegproduced. @-Byfthisnrocedure however, it is difficult to obtain a sui.- ciently even distribution of the material in the mold, for which reason it is preferred to place the molds horizontally, and introduce the material from the broad or large face surface of the plate to be produced.

Since in the preferred method the pressure will have to act through a longer distance of material than in the method where the molds stand on edge, I have found that in order to obtain a substantially uniform structure in all portions of the finished plate. it is desirable to add an excess of material at the centre portion of the plate than at the end portions thereof. Also, for this Figure 1.

' vice (not shown).

reason. it is preferable to use horizontally arranged pressure molds, which are filled from a large face thereof. For filling of the centre portion of the mold there may suitably be made use of an auxiliary frame and of an auxiliary pressure piston, which will be fully described below.

For more or less filling up of the spaces between the fiber strips o'f the plate, the mass to be pressed may have added thereto some "short material, such as saw dust, wood chips and the like. Such shorter additional stuff is preferably added near the external surfaces of the plate, whereas the inner part of the plate receives no such addition, or to a lesser degree only.

For a better understanding of the invention the method will now be describedin connection` with the drawing, illustrating an embodiment of the invention;

Figure 1 shows diagrammatically a vertical section through a stack of molds.

Figure 2 illustrates diagrammatically an auxiliary frame and an auxiliaryrpressure piston, Y which are used when lling the mold.

On a suitable support is placed a bottom board I having the same length, or somewhat more, than the plate to beI manufactured. Then are placed in position side members a, and b of the same length as said bottom board l. These side members confine the longitudinal sides of the molding space and serveA also as pistons during pressing of the plate. The outermost positions of the side members are controlled by stops (not shown). -Into the now open mold is introduced material to be pressed. Then is placed over the mold an intermediate board 2, and suitably thereover still another intermediate board 3. Thereafter anew set ofvside members a.' and b is board 4. 'Then the4 stack of molds is pressed vertically so `that thel plates havethe desired thickness.

This position of the molds is then secured by any rdesired means which may be some planks or the like,`which are arranged below and over the stack and are secured to each other by means of through bolt with nuts screwed vthereon (not shown); Then the side members a, b, a', b etc. are pressed inwards simultaneously and to the same degree, preferably a distance a: as indicated on the right lower part of When the side members have been pressed in they are secured in position by means of vertically disposed-planks or the like and bolts passngtherethrough, `or by a similar de- Then4 the entire body remains until the bonding agent has set, at which time the stackis opened and the plates are removed. If a ash occurs along the sides of -two opposite the pressed plate it may easily be removed by milling or filing. As indicated on the drawing the side portions may be provided with grooves and tongues, which become very sharp and accurate by this pressure method.

As mentioned above it is preferable to apply an excess of material at the Icenter portion of the mold as compated to the sides thereof. In order that all molds shall be lled in an equal manner at the center it is advantageous to make use of a device shown diagrammatically in Figure 2. Over the end members of the open mold is placed an open frame 5, which extends 1ongitudinally of the mold along the center portion thereof. Into this frame is lled a desired quantity of extra material, which latter is then pressed down into the mold below. The piston 6 and the frame 5 may then immediately be removed. since experience has shown that the mass originally contained in the frame will not expand too much. If the piston 6 is moved down some few centimeters below the top edge of the side f member, the material will not expand more than to become ush with the top of said side members. Filling in of material along the sides of the mold. may take place simultaneously as the lling of the auxiliary frame 5.

I claim:

1. A method of manufacturing a cement-fibre mass adapted for building construction, which includes the steps of confining the mass within a form to have face surfaces and smaller side surfaces, and subjecting the mass which consists of a liquid mixture of a bonding agent and strips of brous material having a cross-section the width of which is substantially greater than its thickness to a compressive force in a direction parallel to the face surfaces of the mass so as to orient the width dimension of the fibre strips substantially perpendicular to said face surfaces of the mass. v

2. Method according to claim 1 wherein the width of the respective fibre strips is at least twice as great as the thickness of the strip.

3. Method according to claim 2 wherein the compressive force is exerted from a side surface of the mass.

4. Method according to claim 2 wherein the compressive force is exerted simultaneously from side surfaces of the mass.

SVERRE WILFRED EVENSEN.

REFERENCES CITED The following references are of record in the A le of this patent:

UNITED STATES PATENTS Number: Name Y Date 2,120,268 Schuh June 14, 1938 2,377,484 Elmendorf June 5, 1945 2,476,653 Elberty, Jr. July 19, 1949 

